Laser irradiation apparatus and method for manufacturing semiconductor device

ABSTRACT

A laser irradiation apparatus (1) according to an embodiment includes an optical-system module (20) configured to apply laser light (L1) to an object to be irradiated, a shield plate (51) in which a slit (54) is formed, through which the laser light (L1) passes, and a reflected-light receiving component (61) disposed between the optical-system module (20) and the shield plate (51), in which the reflected-light receiving component (61) is able to receive, out of the laser light (L1), reflected light (R1) reflected by the shield plate (51).

TECHNICAL FIELD

The present invention relates to a laser irradiation apparatus and amethod for manufacturing a semiconductor device. For example, thepresent invention relates to a laser irradiation apparatus thatirradiates an amorphous film formed over a substrate with laser lightand thereby performs a laser annealing process, and a method formanufacturing a semiconductor device.

BACKGROUND ART

A laser annealing apparatus that irradiates an amorphous film formedover a silicon substrate or a glass substrate with laser light andthereby crystallizes the amorphous film has been known. PatentLiterature 1 and 2 each disclose a laser annealing apparatus that blocksan edge part of laser light on a cross section orthogonal to an opticalaxis thereof, in which intensity decreases, by making the laser lightpass through a slit, and uses the obtained laser light having uniformintensity as irradiation light.

CITATION LIST Patent Literature

Patent Literature 1: Japanese Patent No. 5717146

Patent Literature 2: Japanese Patent No. 5907530

SUMMARY OF INVENTION Technical Problem

In the laser annealing apparatus disclosed in Patent Literature 1 and 2,the edge part of the laser light on the cross section orthogonal to theoptical axis thereof does not pass through the slit and is blocked by ashield part forming the slit. It is conceivable that the laser lightblocked by the shield part is reflected by the shield part.

It is conceivable that the reflected light reflected by the shield partreaches an optical-system module of the laser annealing apparatus andthereby adversely affects the optical-system module such as raising atemperature of the optical-system module. In that case, a housing of theoptical-system module is deformed by a thermal stress, causing apositional deviation of each optical element provided in theoptical-system module. It is conceivable that, as a result, unevenirradiation occurs in the laser light for crystallizing the amorphousfilm, thus making it impossible to carry out a stable crystallizingprocess.

Further, reflected light of the laser light that has passed through theslit, reflected by the amorphous film or the substrate travels throughthe slits in the opposite direction and reaches the optical-systemmodule. It is conceivable that, as a result, uneven irradiation occursin a manner similar to that caused by the reflected light reflected bythe shield part.

Other problems to be solved and novel features will become apparent fromdescriptions in this specification and accompanying drawings.

Solution to Problem

A laser irradiation apparatus according to an embodiment includes: anoptical-system module configured to apply laser light to an object to beirradiated; a first shield plate in which a first slit is formed,through which the laser light passes; and a reflected-light receivingcomponent disposed between the optical-system module and the firstshield plate, in which the reflected-light receiving component is ableto receive, out of the laser light, first reflected light reflected bythe first shield plate.

A method for manufacturing a semiconductor device according to anembodiment includes: (A) a step of emitting laser light from anoptical-system module toward a substrate on which a film including asemiconductor is formed; (B) providing a first shield plate in which afirst slit is formed, through which the laser light passes, and making,out of the laser light applied to the first slit and the first shieldplate, part of the laser light applied to the first slit pass throughthe first slit; (C) blocking, out of the laser light applied to thefirst slit and the first shield plate, part of the laser light appliedto the first shield plate by the first shield plate; (D) disposing areflected-light receiving component between the optical-system moduleand the first shield plate, and making the reflected-light receivingcomponent receive a first reflected light, the first reflected lightbeing light that is generated as the laser light is applied to the firstshield plate and reflected by the first shield plate; and (E)irradiating the substrate with, out of the laser light applied to thefirst slit and the first shield plate, the laser light that has passedthrough the first slit.

Advantageous Effects of Invention

According to the above-described embodiment, it is possible to provide alaser irradiation apparatus and a method for manufacturing asemiconductor device capable of preventing uneven irradiation andcarrying out a stable crystallizing process.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a cross section showing an example of a laser irradiationapparatus according to a first embodiment;

FIG. 2 is a cross section showing an example of a main part of the laserirradiation apparatus according to the first embodiment;

FIG. 3 is a cross section of the main part of the laser irradiationapparatus taken along a cutting line A-A in FIG. 2;

FIG. 4 is a cross section of the main part of the laser irradiationapparatus taken along a cutting line B-B in FIG. 2;

FIG. 5 is a perspective view showing an example of a relation betweenlaser light and a slit in the laser irradiation apparatus according tothe first embodiment;

FIG. 6 is a flowchart showing an example of a laser irradiation methodusing the laser irradiation apparatus according to the first embodiment;

FIG. 7 is a cross section showing an example of a laser irradiationapparatus according to a comparative example;

FIG. 8 is an enlarged view showing examples of shapes of laser light ona substrate when being applied to the substrate;

FIG. 9 is a cross section showing an example of a main part of a laserirradiation apparatus according to a second embodiment;

FIG. 10 is a cross section showing an example of a reflected-lightreceiving component according to the second embodiment;

FIG. 11 is a cross section of the reflected-light receiving componenttaken along a cutting line C-C in FIG. 10;

FIG. 12 is a cross section showing an example of a main part of a laserirradiation apparatus according to a third embodiment;

FIG. 13 is a cross section showing an example of a reflected-lightreceiving component according to the third embodiment;

FIG. 14 is a cross section showing an example of a heat absorbingelement according to a third embodiment;

FIG. 15 is a cross section showing an example of a method formanufacturing a semiconductor device according to a fourth embodiment;and

FIG. 16 is a cross section for explaining an outline of an organic ELdisplay, in which pixel circuits of the organic EL display are shown ina simplified manner.

DESCRIPTION OF EMBODIMENTS First Embodiment

A laser irradiation apparatus according to a first embodiment isdescribed. The laser irradiation apparatus according to this embodimentis an apparatus that applies laser light to an object to be irradiated.The object to be irradiated is, for example, a substrate on which a filmincluding a semiconductor, such as an amorphous film, is formed. In thiscase, the laser irradiation apparatus performs a laser annealing processfor crystallizing the amorphous film by irradiating the amorphous filmwith laser light. For example, when a laser annealing process isperformed by using an excimer laser as the laser light, the laserirradiation apparatus is used as an excimer laser annealing (ELA:Excimer Laser Anneal) apparatus.

Firstly, a configuration of the laser irradiation apparatus isdescribed. FIG. 1 is a cross section showing an example of a laserirradiation apparatus according to the first embodiment. FIG. 2 is across section showing an example of a main part of the laser irradiationapparatus according to the first embodiment. FIG. 3 is a cross sectionof the main part of the laser irradiation apparatus taken along acutting line A-A in FIG. 2. FIG. 4 is a cross section of the main partof the laser irradiation apparatus taken along a cutting line B-B inFIG. 2. FIG. 5 is a perspective view showing an example of a relationbetween laser light and a slit in the laser irradiation apparatusaccording to the first embodiment.

As shown in FIG. 1, the laser irradiation apparatus 1 includes a lightsource 10, an optical-system module 20, a sealed part 30, and aprocessing chamber 40. The processing chamber 40 is disposed, forexample, over a horizontal base 48. The sealed part 30 is disposed abovethe processing chamber 40 and the optical-system module 20 is disposedabove the sealed part 30. The optical-system module 20 is disposed in aplace where it can receive laser light L1 emitted from the light source10.

Here, XYZ orthogonal coordinate axes are introduced to explain the laserirradiation apparatus 1. A direction orthogonal to the top surface ofthe base 48 is defined as a Z axis direction. Further, an upwarddirection is defined as a +Z axis direction and a downward direction isdefined as a −Z axis direction. A direction connecting the light source10 and the optical-system module 20 is defined as an X axis direction.Further, a direction from the light source 10 toward the optical-systemmodule 20 is defined as a +X axis direction and the opposite directionis defined as a −X axis direction. The direction orthogonal to the Xaxis and Z axis directions is defined as a Y axis direction. Further,one direction along the Y direction is defined as a +Y axis directionand the opposite direction is defined as a −Y axis direction.

As shown in FIG. 1, the light source 10 emits laser light L1. The lightsource 10 is, for example, an excimer laser light source and emits laserlight L1, which is an excimer laser having a center wavelength of 308nm. Further, the light source 10 emits pulsed laser light L1. The lightsource 10 emits the laser light L1 toward the optical-system module 20.For example, the laser light L1 travels in the +X axis direction andenters the optical-system module 20. Note that, if necessary, an opticalelement(s) for adjusting an energy density, such as an attenuator, maybe disposed on an optical path of the laser light L1 between the lightsource 10 and the optical-system module 20.

As shown in FIGS. 1-4, the optical-system module 20 includes anoptical-system housing 21 constituting an external shape thereof, amirror 22, an optical element(s) such as a lens, and a sealing window23. The optical-system housing 21 is, for example, a box-like componentmade of aluminum or the like. Each of the optical elements of theoptical-system module 20 is held by a holder or the like inside theoptical-system housing 21. With these optical elements, theoptical-system module 20 adjusts an emitting direction, an amount, andthe like of the laser light L1 emitted from the light source 10. Thesealing window 23 is disposed in a part of the optical-system housing21, e.g., over the bottom surface of the optical-system housing 21.After being adjusted by the optical-system module 20, the laser light L1is emitted from the sealing window 23 toward the sealed part 30. In thismanner, the optical-system module 20 applies the laser light L1 to anobject to be irradiated.

As shown in FIG. 5, the laser light L1 is in the form of a line beam inthe optical-system module 20. That is, a cross section of the laserlight L1 orthogonal to an optical axis C1 thereof is an elongated linearshape extending in one direction. For example, the cross section of thelaser light L1 reflected by the mirror 22 orthogonal to the optical axisthereof has a linear shape extending in the Y axis direction.

As shown in FIGS. 2 to 4, the sealed part 30 includes a sealed housing31, a shield plate 51, a reflected-light receiving component 61, asealing window 33, a gas inlet 34, and a gas outlet 35. For simplifyingthe figure, the gas inlet 34 and the gas outlet 35 are omitted in FIG.3. Further, the reflected-light receiving component 61, the sealingwindow 33, the gas inlet 34, and the gas outlet 35 are omitted in FIG.4. Note that for clarity of the description, each drawing is simplifiedas appropriate.

The sealed housing 31 is a box-like hollow component. The shield plate51 and the reflected-light receiving component 61 are disposed insidethe sealed housing 31. The gas inlet 34 and the gas outlet 35 aredisposed on predetermined side surfaces of the sealed housing 31. Thegas inlet 34 and the gas outlet 35 are disposed, for example, on opposedside surfaces of the sealed housing 31. For example, the gas outlet 35is disposed in a position higher than the gas inlet 34. A gas 37, whichis, for example, an inert gas such as nitrogen, is fed from the gasinlet 34. The gas 37 fed into the sealed housing 31 from the gas inlet34 is discharged from the gas outlet 35. It is preferable that the gas37 is continuously supplied into the sealed housing 31. Further, it ispreferable that the gas 37 is continuously discharged to the outside ofthe sealed housing 31. A flow rate of the gas 37 is controlled to apredetermined flow rate so that the internal space of the sealed housing31 is always ventilated.

As shown in FIGS. 2 to 5, the shield plate 51 is disposed on an opticalpath through which the laser light L1 emitted from the sealing window 23of the optical-system module 20 reaches the processing chamber 40. Theshield plate 51 includes, for example, a plurality of components. Theshield plate 51 includes, for example, a shield plate 51 a and a shieldplate 51 b. Each of the shield plates 51 a and 51 b is a plate-likecomponent extending in one direction, e.g., extending in the Y axisdirection. The shield plates 51 a and 51 b are disposed in such a mannerthat their plate surfaces face the Z axis direction. The shield plates51 a and 51 b are arranged side by side with a space therebetween in theY axis direction. Therefore, a slit 54 is formed between the shieldplates 51 a and 51 b. Each of the shield plates 51 a and 51 b can bemoved by a motor (not shown) in the +Y axis and −Y axis directions, sothat a width of the slit 54 (a distance between the shield plates 51 aand 51 b) can be set as desired. The laser light L1 passes through theslit 54. As described above, the slit 54, through which the laser lightL1 passes, is formed in the shield plate 51.

Both edges of the laser light L1 in the Y axis direction are blocked bythe shield plates 51 a and 51 b. The edge part of the laser light L1blocked by the shield plates 51 a and 51 b are reflected by the shieldplates 51 a and 51 b and become reflected light R1. In this way, out ofthe laser light L1 applied to the slit 54 and the shield plate 51, partof the laser light L1 blocked by the shield plate 51 is reflected by theshield plate 51.

A reflecting mirror 57 may be provided over a surface on theoptical-system module 20 side of the shield plate 51. In this way, it ispossible to prevent the laser light L1 blocked by the shield plate 51from being absorbed in the shield plate 51. Therefore, it is possible toprevent an atmosphere near the shield plate 51 from being disturbed,which would otherwise be caused by a rise in temperature of the shieldplate 51. It is preferable that a reflecting film applied to thereflecting mirror 57 has been processed so as to have a predeterminedtolerance for the incident angle of the laser light L1. In general,there are various reflecting films from those whose reflectance changesdrastically according to the incident angle of the laser light L1 tothose whose reflectance does not change much according to the incidentangle of the laser light L1. In this embodiment, a reflective film whosereflectance remains within a predetermined range irrespective of changesin incident angle of the laser light L1 that could possibly occur whenlaser light is applied to an object to be irradiated.

The reflected-light receiving component 61 is disposed between theshield plate 51 and the optical-system module 20. For example, thereflected-light receiving component 61 is disposed outside theoptical-system module 20 in such a manner that a space is formed betweenthe reflected-light receiving component 61 and the optical-system module20. The reflected-light receiving component 61 is, for example, aplate-like component. The reflected-light receiving component 61 isdisposed in such a manner that its plate surface faces the Z axisdirection. The reflected-light receiving component 61 is disposed so asto be able to receive the reflected light R1, which is generated as thelaser light L1 that has been blocked by the shield plate 51 is reflectedby the shield plate 51. For example, the reflected-light receivingcomponent 61 is disposed on an optical path of the reflected light R1while taking the incident angle of the laser light L1 and the reflectionangle of the reflected light R1 into consideration. Note that thereflected-light receiving component 61 may be attached to theoptical-system module 20 with a heat-insulating material interposedtherebetween so that a space is formed therebetween. In this way, it ispossible to maintain a heat-insulating property between thereflected-light receiving component 61 and the optical-system module 20.

The sealing window 33 is disposed in a part of the sealed housing 31,e.g., over the bottom surface of the sealed housing 31. The laser lightL1 emitted from the sealing window 23 of the optical-system module 20passes through the slit 54 between the shield plates 51. Then, the laserlight L1, which has passed through the slit 54, is emitted from thesealing window 33 toward the processing chamber 40.

As shown in FIG. 1, the processing chamber 40 includes a gas box 41, ashield plate 52, a substrate stage 45, a base 46, and a scanning device47. For example, in the processing chamber 40, the laser light L1 isapplied to a substrate M1 placed over the substrate stage 45, so that alaser annealing process for crystallizing an amorphous film formed overthe substrate M1 is performed. The substrate stage 45 may be afloat-type stage, i.e., a stage that transports the substrate M1, whichis an object to be irradiated, while levitating the substrate M1.

As shown in FIGS. 2 and 3, the gas box 41 is a box-like hollowcomponent. The gas box 41 is disposed above the substrate stage 45 andbelow the sealing window 33 of the sealed part 30. An inlet window 42 isprovided over the top surface of the gas box 41. The inlet window 42 isdisposed so as to be opposed to the sealing window 33. Further, anirradiation window 43 is provided over the bottom surface of the gas box41. The irradiation window 43 is disposed so as to be opposed to theamorphous film formed over the substrate M1.

A gas inlet 44 is provided in a predetermined side surface of the gasbox 41. A predetermined gas 37, which is, for example, an inert gas suchas nitrogen, is supplied from the gas inlet 44 into the gas box 41. Thegas 37 supplied into the gas box 41 fills the internal space of the gasbox 41 and then is discharged from the irradiation window 43.

The shield plate 52 is disposed on an optical path through which thelaser light L1 emitted from the sealing window 33 of the sealed part 30reaches the amorphous film formed over the substrate M1. The shieldplate 52 is disposed, for example, so as to cover the irradiation window43 inside the gas box 41.

As shown in FIGS. 3 and 5, the shield plate 52 includes, for example, aplurality of components. The shield plate 52 includes, for example, ashield plate 52 a and a shield plate 52 b. Each of the shield plates 52a and 52 b is a plate-like component extending in one direction. Theshield plates 52 a and 52 b are arranged so that their plate surfacesface the Z axis direction and their extending direction is in parallelwith the Y direction. The shield plates 52 a and 52 b are arranged sideby side with a space therebetween in the Y axis direction. Therefore, aslit 55 is formed between the shield plates 52 a and 52 b. Each of theshield plates 52 a and 52 b can be moved by a motor (not shown) in the+Y axis and −Y axis directions, so that a width of the slit 55 (adistance between the shield plates 52 a and 52 b) can be set as desired.The laser light L1 passes through the slit 55. As described above, theslit 55, through which the laser light L1 which has already passedthrough the slit 54 passes, is formed in the shield plate 52.

Both edges of the laser light L1 in the Y axis direction are blocked bythe shield plates 52 a and 52 b. The edge parts of the laser light L1blocked by the shield plates 52 a and 52 b are reflected by the shieldplates 52 a and 52 b and become reflected light R2. In this way, out ofthe laser light L1 applied to the slit 55 and the shield plate 52, partof the laser light L1 blocked by the shield plate 52 is reflected by theshield plate 52.

The reflected-light receiving component 61 is disposed so as to be ableto receive the reflected light R2, which is, out of the laser light L1applied to the slit 55 and the shield plate 52, the part of the laserlight L1 that has been blocked by the shield plate 52 and reflected bythe shield plate 52.

A reflecting mirror 57 may be provided over a surface on theoptical-system module 20 side of the shield plate 52. In this way, it ispossible to prevent the laser light L1 blocked by the shield plate 52from being absorbed in the shield plate 52. Therefore, it is possible toprevent an atmosphere near the shield plate 52 from being disturbed,which would otherwise be caused by a rise in temperature of the shieldplate 52. It is preferable that a reflecting film included in thereflecting mirror 57 has been processed so as to have a predeterminedtolerance for the incident angle of the laser light L1.

The laser light L1 that has passed through the slit 55 between theshield plates 52 is emitted from the irradiation window 43 and appliedto the amorphous film formed over the substrate M1.

The substrate M1 is placed over the substrate stage 45. The substrate M1is, for example, a semiconductor substrate such as a silicon substrate,or a quartz substrate or the like. Note that the substrate M1 is notlimited to the semiconductor substrate and the quartz substrate. A filmincluding a semiconductor, such as an amorphous film, is formed over thesubstrate M1. The amorphous film contains, for example, amorphoussilicon (aSi). The amorphous film formed on the substrate M1 isirradiated with the laser light L1 and thereby crystallized. Bycrystallizing the amorphous film, for example, a crystalline filmcontaining polysilicon (polySi) is formed over the substrate M1.

The laser light L1 applied to the amorphous film formed over thesubstrate M1 is reflected by the amorphous film or the substrate M1 andbecomes reflected light R3. The reflected-light receiving component 61is disposed so as to be able to receive the reflected light R3, which isgenerated as the laser light L1 that has been applied to the amorphousfilm or the substrate M1 is reflected by the amorphous film or thesubstrate M1.

As shown in FIG. 1, the substrate stage 45 is placed, for example, abovethe scanning device 47 with the base 46 interposed therebetween. Thesubstrate stage 45 can be moved in the X axis, the Y axis, and the Zaxis directions by the scanning device 47. When a laser annealingprocess is performed, the substrate stage 45 is transported in atransport direction 49, which is, for example, the −X axis direction, bya scanning operation performed by the scanning device 47.

Next, a laser irradiation method using the laser irradiation apparatus 1according to the first embodiment is described.

FIG. 6 is a flowchart showing an example of a laser irradiation methodusing the laser irradiation apparatus according to the first embodiment.

As shown in a step S11 in FIG. 6, firstly, laser light L1 is emittedfrom the optical-system module 20. After an emitting direction, anamount, and the like of the laser light L1 emitted from the light source10 are adjusted by the optical-system module 20, the laser light L1 isemitted to the sealed part 30. For example, in the case where an objectto be irradiated is a substrate M1 on which a film containing asemiconductor, such as an amorphous film, is formed, laser light isemitted from the optical-system module toward the substrate M1.

Next, as shown in a step S12 in FIG. 6, the laser light L1 is made topass through the slit formed in the shield plate 51. That is, a shieldplate 51 in which a slit 54 is formed, through which the laser light L1passes, is provided and, out of the laser light L1 applied to the slit54 and the shield plate 51, part of the laser light L1 that has beenapplied to the slit 54 is made to pass through the slit 54. Further, ashield plate 52 in which a slit 55 is formed is provided and, out of thelaser light L1 that has passed through the slit 54 and has been appliedto the slit 55 and the shield plate 52, part of the laser light L1 thathas been applied to the slit 55 is made to pass through the slit 55.

Next, as shown in a step S13 in FIG. 6, out of the laser light L1applied to the slit 54 and the shield plate 51, part of the laser lightL1 that has been applied to the shield plate 51 is blocked by the shieldplate 51. Further, out of the laser light L1 applied to the slit 55 andthe shield plate 52, part of the laser light L1 that has been applied tothe shield plate 52 is blocked by the shield plate 52. In this way, on across section of the laser light L1 orthogonal to an optical axisthereof, the edge part of the laser light L1 is blocked and the part ofthe laser light L1 other than the edge part thereof is used to irradiatethe object to be irradiated.

Next, as shown in a step S14 in FIG. 6, the reflected-light receivingcomponent 61 is made to receive reflected light R1 which is generated asthe laser light L1 is reflected by the shield plate 51. That is, thereflected-light receiving component 61 is disposed between theoptical-system module 20 and the shield plate 51, and thereflected-light receiving component 61 is made to receive the reflectedlight R1, which is generated as the laser light L1 that has been appliedto the shield plate 51 is reflected by the shield plate 51. Further, thereflected-light receiving component 61 is made to receive reflectedlight R2 which is generated as the laser light L1 that has been appliedto the shield plate 52 is reflected by the shield plate 52.

Next, as shown in a step S15 in FIG. 6, the object to be irradiated isirradiated with the laser light L1. That is, out of the laser light L1applied to the slit 54 and the shield plate 51, the laser light L1 thathas passed through the slit 54 is applied to the object to beirradiated. In the case where the object to be irradiated is a substrateon which a film containing a semiconductor, such as an amorphous film,is formed, the laser light L1 is applied to the amorphous film.Specifically, the laser light L1 is applied to the amorphous film formedover the substrate M1 while transporting the substrate M1 in a transportdirection 49 of the substrate M1, which is, for example, the −X axisdirection. Further, the reflected-light receiving component 61 is madeto receive reflected light R3 which is generated as the laser light L1that has been applied to the substrate M1 is reflected by the substrateM1.

In this way, it is possible to perform laser irradiation by using thelaser irradiation apparatus 1 according to the first embodiment.

Next, advantageous effects of the laser irradiation apparatus 1according to the first embodiment are described. The laser irradiationapparatus 1 according to this embodiment includes the reflected-lightreceiving component 61. The reflected-light receiving component 61 isdisposed so as to receive the reflected light R1 reflected by the shieldplate 51, the reflected light R2 reflected by the shield plate 52, andthe reflected light R3 reflected by the object to be irradiated.Therefore, it is possible to prevent the reflected lights R1 to R3 fromreaching the optical-system module 20. In particular, it is possible toprevent an occurrence of a positional deviation of each optical element,which would otherwise be caused as the reflected light R1 reflected bythe shield plate 51 enters inside the optical-system module 20 andreaches a holder of each optical element. Therefore, it is possible tosuppress a rise in temperature of the optical-system module due to theapplication of the reflected lights R1 to R3 and thereby to prevent thehousing of the optical-system module from being deformed. As a result,it is possible to prevent the positional deviation of each opticalelement provided in the optical-system module and thereby to preventuneven irradiation by the laser light.

Further, the reflected lights R1 to R3 reach one reflected-lightreceiving component 61. Therefore, it is possible to confine all thefactors that cause a temperature gradient relative to the optical-systemmodule 20 within, for example, the reflected-light receiving component61, and thus making it easy to take measures for suppressing a rise intemperature of the optical-system module 20.

The reflected-light receiving component 61 is not directly attached tothe optical-system module 20, but is disposed so that a space is formedbetween the reflected-light receiving component 61 and theoptical-system module 20. In this way, it is possible to improve aheat-insulating property between the reflected-light receiving component61 and the optical-system module 20. Further, the reflected-lightreceiving component 61 is attached to the optical-system module 20 witha heat-insulating material interposed therebetween so that a space isformed therebetween. In this way, it is also possible to improve theheat-insulating property between the reflected-light receiving component61 and the optical-system module 20.

The reflected-light receiving component 61 is disposed above the sealingwindow 33, which is disposed above the gas box 41. Therefore, even if atemperature in the vicinity of the reflected-light receiving component61 rises as the reflected lights R1 to R3 are received, it is possibleto prevent an atmosphere in the vicinity of the substrate M1 from beingdisturbed because the gas box 41 is disposed between the reflected-lightreceiving component 61 and the substrate M1. Consequently, it ispossible to prevent uneven irradiation, which would otherwise be causeby the disturbance of the atmosphere.

By providing the reflecting mirrors 57 over the surfaces on theoptical-system module 20 side of the shield plates 51 and 52, it ispossible to prevent the laser light L1 from being absorbed in the shieldplates 51 and 52. As a result, it is possible to prevent atmospheresnear the shield plates 51 and 52 from being disturbed, which wouldotherwise be caused by rises in temperatures of the shield plates 51 and52. Therefore, it is possible to prevent uneven irradiation, which wouldotherwise be cause by the disturbance of the atmosphere. By providingthe reflection mirror 57 at least on the shield plate 51, which islocated close to the optical-system module 20, it is possible tosuppress the uneven irradiation, which would otherwise be cause by thedisturbance of the atmosphere.

A flow rate of the gas 37 is controlled so that the internal space ofthe sealed housing 31 is always ventilated. In this way, it is possibleto suppress a rise in temperature in the atmosphere inside the sealedhousing 31. Therefore, it is possible to prevent a refractive index fromfluctuating, which would otherwise be caused as a fluid density changesdue to a temperature gradient of the atmosphere through which the laserlight L1 passes, and thereby to prevent uneven irradiation.

Comparative Example

Next, a comparative example is described. Then, an effect of suppressingan influence of heat of reflected light on a long axis of laser lightwill be described by comparing the comparative example with the firstembodiment.

FIG. 7 is a cross section showing an example of a laser irradiationapparatus according to a comparative example. As shown in FIG. 7, alaser irradiation apparatus 101 according to the comparative exampledoes not include the reflected-light receiving component 61. Therefore,the reflected light R1 reflected by the shield plate 51, the reflectedlight R2 reflected by the shield plate 52, and the reflected light R3reflected by the object to be irradiated reach the optical-system module20. In particular, the reflected light R1 reflected by the shield plate51 enters into the optical-system module 20 through the sealing window23 and reaches a holder of each optical element. Therefore, heat of thereflected lights R1 to R3 is transmitted to the optical-system moduleand the holder of each optical element, and thereby raises theirtemperatures. As a result, the optical-system housing 21 and the holderof each optical element are deformed, thus causing a positionaldeviation of each optical element provided in the optical-system module20.

(Shape of Laser Light L1 over Substrate M1)

FIG. 8 is an enlarged view showing examples of shapes of the laser lightL1 over the substrate M1 when being applied to the substrate M1. Asshown in FIG. 8, regarding the configuration of the reflected-lightreceiving component, the comparative example includes no reflected-lightreceiving component and the first embodiment includes only a main-bodypart of the reflected-light receiving component. Note that a secondembodiment will be described later.

Regarding the shape of the laser light L1 over the substrate M1, aninclination is within an error range of about 0 μm immediately afterlaser irradiation in the comparative example. However, when seven hoursor longer has elapsed after the laser irradiation, the inclination isabout 250 μm in the comparative example. That is, it is significantlyinclined to such a degree that uneven irradiation occurs in the laserirradiation.

Meanwhile, regarding the shape of the laser light L1 over the substrateM1, an inclination is within an error range of about 0 μm immediatelyafter laser irradiation in the first embodiment. When seven hours orlonger has elapsed after the laser irradiation, the inclination is about50 μm in the first embodiment. That is, the inclination is such a degreethat uneven irradiation in the laser irradiation is within a permissiblerange.

As described above, in the first embodiment, by providing thereflected-light receiving component 61, it is possible to suppress arise in temperature of the optical-system module 20 due to theapplication of the reflected lights R1 to R3 and thereby to prevent apositional deviation of each optical element provided in theoptical-system module 20. Therefore, it is possible to prevent unevenirradiation by the laser light L1.

Second Embodiment

Next, a laser irradiation apparatus according to a second embodiment isdescribed. FIG. 9 is a cross section showing an example of a main partof a laser irradiation apparatus according to the second embodiment.FIG. 10 is a cross section showing an example of a reflected-lightreceiving component according to the second embodiment. FIG. 11 is across section of the reflected-light receiving component taken along acutting line C-C in FIG. 10.

As shown in FIG. 9 to FIG. 11, in the laser irradiation apparatus 2according to this embodiment, a reflected-light receiving component 62is also provided between the shield plate 51 and the optical-systemmodule 20. For example, the reflected-light receiving component 62 isattached to the optical-system module 20 with a heat-insulating material58 interposed therebetween so that a space is formed therebetween. Thereflected-light receiving component 62 is, for example, a plate-likecomponent. The reflected-light receiving component 62 is disposed insuch a manner that its plate surface faces the Z axis direction. Notethat the reflected-light receiving component 62 may be disposed outsidethe optical-system module 20 in such a manner that a space is formedbetween the reflected-light receiving component 62 and theoptical-system module 20, instead of being attached to theoptical-system module 20 with the heat-insulating material 58 interposedtherebetween. In this way, it is possible to maintain a heat-insulatingproperty between the reflected-light receiving component 60 and theoptical-system module 20.

The reflected-light receiving component 62 includes a main-body part 62a and a heat-insulating air layer 62 b containing air. The main-bodypart 62 a is disposed so as to receive reflected light R1, reflectedlight R2, and reflected light R3. The heat-insulating air layer 62 b isdisposed on the optical-system module 20 side of the main-body part 62a. For example, the main-body part 62 a and the heat-insulating airlayer 62 b are stacked in a plate-surface direction of thereflected-light receiving component 62. An intake port (not shown) andan exhaust port (not shown) are formed in the heat-insulating air layer62 b. The internal space of the heat-insulating air layer 62 b can beventilated by supplying a predetermined gas such as air from the intakeport and exhausting the gas from the exhaust port.

By using the above-described configuration, it is possible to preventheat that is generated as the main-body part 62 a receives reflectedlight from been transmitted to the optical-system module 20. Note that agas other than air may be supplied to and discharged from theheat-insulating air layer 62 b as long as the heat-insulating propertybetween the reflected-light receiving component 62 and theoptical-system module 20 can be improved. Further, a pressure inside theheat-insulating air layer 62 b may be changed.

A coolant channel 62 c through which a coolant flows is provided in themain-body part 62 a of the reflected-light receiving component 62.Therefore, the reflected-light receiving component 62 includes a coolingjacket including the coolant channel 62 c through which a coolant flows.For example, the coolant channel 62 c is laid out so as to meander on aplane parallel to the plate surface inside the main-body part 62 a. Aninlet and an outlet of the coolant flowing through the coolant channel62 c are provided on side surfaces of the main-body part 62 a. In thisway, the coolant supplied from the inlet of the coolant channel 62 ccirculates through the coolant channel 62 c and is discharged from theoutlet of the coolant channel 62 c. A temperature of the coolant isadjusted to a predetermined temperature.

The rest of the configuration of the laser irradiation apparatus 2according to the second embodiment is similar to that of the firstembodiment and therefore its description is omitted.

A laser irradiation method using the laser irradiation apparatus 2according to the second embodiment is similar to the laser irradiationmethod using the laser irradiation apparatus 1 according to the firstembodiment, except that the reflected-light receiving component 62 isused in place of the reflected-light receiving component 61. Further,air or the like is supplied to and discharged from the heat-insulatingair layer 62 b of the reflected-light receiving component 62, and acoolant is supplied to and discharged from the coolant channel 62 c. Therest of the laser irradiation method is similar to that of the firstembodiment and therefore its description is omitted.

Next, advantageous effects of the laser irradiation apparatus accordingto the second embodiment are described. The reflected-light receivingcomponent 62 of the laser irradiation apparatus 2 according to thisembodiment includes the cooling jacket. That is, the main-body part 62 aincludes the coolant channel 62 c through which a coolant flows.Therefore, it is possible to suppress a rise in temperature of thereflected-light receiving component 62 due to heat of received reflectedlights R1 to R3. As a result, it is possible to prevent the temperatureof the optical-system module 20 from rising, which would otherwise becaused by radiant heat from the reflected-light receiving component 62.

As shown in FIG. 8, regarding the reflected-light receiving component,the second embodiment includes the cooling jacket (the main-body part 62a and the coolant channel 62 c) and the heat-insulating air layer 62 b.Regarding the shape of the laser light L1 on the substrate M1, aninclination is within an error range of about 0 μm immediately afterlaser irradiation in the second embodiment. When seven hours or longerhas elapsed after the laser irradiation, the inclination can be keptfrom exceeding 10 μm in the second embodiment. That is, it is possibleto keep uneven irradiation in the laser irradiation within a permissiblerange.

As described above, in the second embodiment, by the reflected-lightreceiving component 62, it is possible to suppress a rise in temperatureof the optical-system module due to the application of the reflectedlights R1 to R3. Therefore, it is possible to prevent a positionaldeviation of each optical element provided in the optical-system moduleand thereby to prevent uneven irradiation by the laser light.

It is possible to evacuate the internal space of the heat-insulating airlayer 62 b. By using the above-described configuration, it is possibleto prevent heat that is generated as the main-body part 62 a receivesreflected light from being transmitted to the optical-system module 20.Further, the heat-insulating air layer 62 b has a function of thermallyinsulating the optical-system module 20 from the main-body part 62 a.Therefore, even when a temperature of the coolant in the coolant channel62 c is lower than that of the optical-system module 20, it is possibleto prevent the temperature of the optical-system module 20 fromdecreasing, and thereby to prevent occurrences of positional deviationsof optical elements, which would otherwise be caused by a thermalstress.

Further, the reflected lights R1 to R3 reach one reflected-lightreceiving component 62. Therefore, it is possible to confine all theplaces that are cooled by the coolant within the reflected-lightreceiving component 62, and thus making it easy to take measures forsuppressing a rise in temperature of the optical-system module 20. Otheradvantageous effects are similar to those of the first embodiment andtherefore their descriptions are omitted.

Third Embodiment

Next, a laser irradiation apparatus according to a third embodiment isdescribed. FIG. 12 is a cross section showing an example of a main partof a laser irradiation apparatus according to the third embodiment. FIG.13 is a cross section showing an example of a reflected-light receivingcomponent according to the third embodiment. FIG. 14 is a cross sectionshowing an example of a heat absorbing element according to the thirdembodiment.

As shown in FIGS. 12 to 14, in the laser irradiation apparatus 3according to this embodiment, a reflected-light receiving component 63includes a heat absorbing element 63 d in addition to a cooling jacket(a main-body part 63 a and a coolant channel 63 c) and a heat-insulatingair layer 63 b. Further, a shield plate 71 of the laser irradiationapparatus 3 according to this embodiment is bent toward theoptical-system module 20.

The heat absorbing element 63 d is disposed on the shield plate 71 sideof the reflected-light receiving component 63. The heat absorbingelement 63 d is disposed so as to receive reflected light R1, reflectedlight R2, and reflected light R3. The heat absorbing element 63 d is aplate-like component. The heat absorbing element 63 d is attached to themain-body part 63 a in such a manner that its plate surface faces the Zaxis direction. Therefore, one plate surface of the heat absorbingelement 63 d faces the shield plate 71 side and the other plate surfacethereof faces the optical-system module 20 side.

The heat absorbing element 63 d is a component that absorbs heatcorresponding to wavelengths of the laser light L1 and the reflectedlights R1 to R3, e.g., wavelengths of excimer laser. For example, theheat absorbing element 63 d is a component coated with a plurality ofheat absorbing films that absorb heat. By adjusting a thickness of theheat absorbing films, the number of coating layers to be applied, andthe like, it is possible to adapt the heat absorbing element 63 d to thewavelength of the laser light L1.

As shown in FIG. 14, a multi-layer heat absorbing film 59 a coated witha plurality of heat absorbing films that absorb heat is formed over asurface on the shield plate 71 side of the heat absorbing element 63 d.It is preferable that the multi-layer heat absorbing film 59 a has beenprocessed so as to have a predetermined tolerance for the incidentangles of the reflected lights R1 to R3. In general, there are variousmulti-layer heat absorbing films from those whose heat absorption ratiochanges drastically according to the incident angle of the reflectedlights R1 to R3 to those whose heat absorption ratio does not changemuch according to the incident angle of the reflected lights R1 to R3.In this embodiment, a multi-layer heat absorbing film whose heatabsorption ratio remains within a predetermined range irrespective ofchanges in incident angles of the reflected lights R1 to R3. The heatabsorption ratio of the multi-layer heat absorbing film 59 a on theshield plate 71 side in the heat absorbing element 63 d is set to, forexample, 50%.

Meanwhile, a multi-layer heat absorbing film 59 b is also formed on asurface on the optical-system module 20 side of the heat absorbingelement 63 d. For example, the heat absorption ratio of the multi-layerheat absorbing film 59 b is 98%. As described above, the absorptionratio of the multi-layer heat absorbing film 59 a formed over thesurface on the shield plate 71 side of the heat absorbing element 63 dis lower than that of the multi-layer heat absorbing film 59 b formedover the surface of the optical-system module 20 side of the heatabsorbing element 63 d. By using the above-described configuration, heatabsorbed by the heat absorbing element 63 d can be easily transmitted tothe main-body part 63 a side. Therefore, it is possible to minimizedeterioration of the heat absorbing element 63 d and thereby increase alife of the heat absorbing element 63 d.

Further, the heat absorbing element 63 d may be one for which a frostingprocess has been performed over the surface on the shield plate 71 sidethereof. In this way, it is possible to minimize deterioration of themulti-layer heat absorbing films 59 a and 59 b due to heat of thereflected lights R1 to R3.

The shield plate 71 of the laser irradiation apparatus 3 according tothis embodiment is bent toward the optical-system module 20. Forexample, the shield plate 71 includes a horizontal part 72 and aninclined part 73.

The horizontal part 72 is a horizontal part whose plate surface facesthe Z axis direction. When the shield plate 71 is disposed inside thesealed part 30, it can be fixed by the horizontal part 72. Further, theposition of the shield plate 71 with respect to the optical axis of thelaser light L1 can be easily adjusted by making a fine adjustment to theposition of the horizontal part 72.

The inclined part 73 is a part that is inclined from the horizontal part72 toward the optical-system module 20. The laser light L1 emitted fromthe optical-system module 20 is applied to the slit 54 in the inclinedpart 73 and the inclined part 73. Further, the shield plate 71 isdisposed so that the reflected light R1, which is generated as the laserlight L1 that has been applied to the inclined part 73 is reflected bythe inclined part 73, is received by the heat absorbing element 63 d.

As descried above, the reflected light R1 includes reflected light whichis generated as the laser light L1 that has been applied to the shieldplate 71 is reflected by the inclined part 73. In the part of thereflected-light receiving component 63 where the reflected light R1, thereflected light R2, and the reflected light R3 are received, theincident angle of the reflected light R1 differs from those of thereflected lights R2 and R3. The laser light L1 that has passed throughthe slit 54 in the inclined part 73 is emitted from the sealing window33 toward the processing chamber 40.

The rest of the configuration of the laser irradiation apparatus 3according to the third embodiment is similar to those of the first andsecond embodiments, and therefore its description is omitted.

A laser irradiation method using the laser irradiation apparatus 3according to the third embodiment is similar to the laser irradiationmethod using the laser irradiation apparatus 1 according to the firstembodiment, except that the reflected-light receiving component 63 isused in place of the reflected-light receiving component 61 and theshield plate 71 is used in place of the shield plate 51. Therefore, itsdescription is omitted.

Next, advantageous effects of the laser irradiation apparatus 3according to this embodiment are described. The reflected-lightreceiving component 63 according to this embodiment includes the heatabsorbing element 63 d. Therefore, it is possible to make the heatabsorbing element 63 d absorb heat generated by the reflected lights R1to R3. In this way, it is possible to suppress a rise in temperature ofthe optical-system module 20 due to radiant heat from thereflected-light receiving component 63. Further, it is possible todissipate the heat absorbed by the heat absorption element 63 d by acoolant flowing through the coolant channel 63 c. Therefore, it ispossible to reduce the radiant heat from the reflected-light receivingcomponent 63 and thereby further suppress the rise in temperature of theoptical-system module 20. In this way, it is possible to prevent apositional deviation of each optical element provided in theoptical-system module and thereby to prevent uneven irradiation by thelaser light.

The multi-layer heat absorbing film 59 a has been processed so as tohave a predetermined tolerance for the incident angles of the reflectedlights R1 to R3. Therefore, it is possible to absorb the heat generatedby the reflected lights R1 to R3 irrespective of the incident angles ofthe reflected lights R1 to R3.

The absorption ratio of the multi-layer heat absorbing film 59 a is madesmaller than that of the multi-layer heat absorbing film 59 b. In thisway, it is possible to improve durability of the heat absorbing element63 d and thereby increase a life thereof.

The shield plate 71 is bent toward the optical-system module 20. In thisway, it is possible to bring a place where the reflected light R1reflected by the shield plate 71 is received closer to a place where thereflected lights R2 and R3 are received in the reflected-light receivingcomponent 63. Dependent on the case, it is possible to receive theselights in the same place. Therefore, it is possible to arrange all theplaces to be cooled in a small area and thereby to make the coolingprocess easier. Further, since all the places to be cooled can bearranged in a small area, the size of the heat absorbing element 63 dcan be reduced. Other advantageous effects are similar to those of thefirst and second embodiments and therefore their descriptions areomitted.

Fourth Embodiment: Method for Manufacturing Semiconductor Device

Next, a method for manufacturing a semiconductor device by using theabove-described laser irradiation apparatus is described. In thisembodiment, by using the laser irradiation apparatus as a laserannealing apparatus, it is possible to crystallize an amorphous filmformed over a substrate by applying laser light to the amorphous film.For example, the semiconductor device is a semiconductor deviceincluding TFTs (Thin Film Transistors). In this case, it is possible toform a polysilicon film by applying laser light to an amorphous siliconfilm and thereby crystallizing the amorphous silicon film.

FIGS. 15(a) to 15(e) are cross sections for explaining an example of amethod for manufacturing a semiconductor device according to a fourthembodiment. The laser irradiation apparatus according to theabove-described embodiment is suitable for manufacturing a TFT arraysubstrate. A method for manufacturing a semiconductor device including aTFT is described hereinafter.

Firstly, as shown in FIG. 15(a), a gate electrode 202 is formed over aglass substrate 201. For example, a metal thin film containing aluminumor the like can be used for the gate electrode 202. Next, as shown inFIG. 15(b), a gate insulating film 203 is formed over the gate electrode202. The gate insulating film 203 is formed so as to cover the gateelectrode 202. After that, as shown in FIG. 15(c), an amorphous siliconfilm 204 is formed over the gate insulating film 203. The amorphoussilicon film 204 is disposed so as to be placed over the gate electrode202 with the gate insulating film 203 interposed therebetween.

The gate insulating film 203 is, for example, a silicon nitride film(SiN_(x)), a silicon oxide film (SiO₂ film), or a laminated filmthereof. Specifically, the gate insulating film 203 and the amorphoussilicon film 204 are successively formed by a CVD (Chemical VaporDeposition) method.

Then, as shown in FIG. 15(d), a polysilicon film 205 is formed byapplying laser light to the amorphous silicon film 204 by using thelaser irradiation apparatus described above in the first to thirdembodiments and thereby crystallizing the amorphous silicon film 204. Asa result, the polysilicon film 205 in which silicon is crystallized isformed over the gate insulating film 203.

In this process, it is possible to suppress a rise in temperature of theoptical-system module 20 and thereby to prevent uneven irradiation bythe laser light L1 by using the laser irradiation method using the laserirradiation apparatus according to the above-described first to thirdembodiments. Therefore, it is possible to form a uniformly-crystallizedpolysilicon film 205.

After that, as shown in FIG. 15(e), an inter-layer insulating film 206,a source electrode 207 a, and a drain electrode 207 b are formed overthe polysilicon film 205. The inter-layer insulating film 206, thesource electrode 207 a, and the drain electrode 207 b can be formed byan ordinary photolithography method or an ordinary film forming method.

It is possible to manufacture a semiconductor device including TFTs byusing the above-described method for manufacturing a semiconductordevice. Note that the subsequent manufacturing process will varydepending on the device that is eventually manufactured, and thereforeits description is omitted.

(Organic EL Display)

Next, as an example of a device using a semiconductor device includingTFTs, an organic EL display device is described. FIG. 16 is a crosssection for explaining an outline of an organic EL display device, inwhich pixel circuits of the organic EL display device are illustrated ina simplified manner. The organic EL display device 300 shown in FIG. 16is an active-matrix-type display device in which a TFT is disposed ineach pixel PX.

The organic EL display device 300 includes a substrate 310, a TFT layer311, an organic layer 312, a color filter layer 313, and a sealingsubstrate 314. FIG. 16 shows a top-emission-type organic EL displaydevice, in which the side of the sealing substrate 314 is located on theviewing side. Note that the following description is given to show anexample of a configuration of an organic EL display device and thisembodiment is not limited to the below-described configuration. Forexample, a semiconductor device according to this embodiment may be usedfor a bottom-emission-type organic EL display device.

The substrate 310 is a glass substrate or a metal substrate. The TFTlayer 311 is provided over the substrate 310. The TFT layer 311 includesTFTs 311 a disposed in the respective pixels PX. Further, the TFT layer311 includes wiring lines connected to the TFTs 311 a, and the like. TheTFTs 311 a, the wirings, and the like constitute pixel circuits. Notethat the TFT layer 311 corresponds to the TFT described above withreference to FIG. 16, and includes gate electrodes 202, a gateinsulating film 203, a polysilicon film 205, an inter-layer insulatingfilm 206, source electrodes 207 a, and drain electrodes 207 b.

The organic layer 312 is provided over the TFT layer 311. The organiclayer 312 includes an organic EL light-emitting element 312 a disposedin each pixel PX. The organic EL light-emitting element 312 a has, forexample, a laminated structure in which an anode, a hole injectionlayer, a hole transport layer, a light-emitting layer, an electrontransport layer, an electron injection layer, and a cathode arelaminated. In the case of the top emission type, the anode is a metalelectrode and the cathode is a transparent conductive film made of ITO(Indium Tin Oxide) or the like. Further, in the organic layer 312,separation walls 312 b for separating organic EL light-emitting elements312 a are provided between pixels PX.

The color filter layer 313 is provided over the organic layer 312. Thecolor filter layer 313 includes color filters 313 a for performing colordisplaying. That is, in each pixel PX, a resin layer colored in R (red),G (green), or B (blue) is provided as the color filter 313 a. When whitelight emitted from the organic layer 312 passes through the colorfilters 313 a, the white light is converted into light having RGBcolors. Note that in the case of a three-color system in which organicEL light-emitting elements capable of emitting each color of RGB areprovided in the organic layer 312, the color filter layer 313 may beunnecessary.

The sealing substrate 314 is provided over the color filter layer 313.The sealing substrate 314 is a transparent substrate such as a glasssubstrate and is provided to prevent deterioration of the organic ELlight-emitting elements of the organic layer 312.

Electric currents flowing through the organic EL light-emitting elements312 a of the organic layer 312 are changed by display signals suppliedto the pixel circuits. Therefore, it is possible to control an amount oflight emitted in each pixel PX by supplying a display signalcorresponding to a display image to each pixel PX. As a result, it ispossible to display a desired image.

Note that although the organic EL display device has been describedabove as an example of a device using a semiconductor device includingTFTs, the semiconductor device including TFTs may be other types ofdisplay devices such as a liquid crystal display device. Further, caseswhere the laser irradiation apparatus according to this embodiment isapplied to a laser annealing apparatus have been described above.However, the laser irradiation apparatus according to this embodimentcan also be applied to apparatuses other than the laser annealingapparatus.

The present invention made by the inventors of the present applicationhas been explained above in a concrete manner based on embodiments.However, the present invention is not limited to the above-describedembodiments, and needless to say, various modifications can be madewithout departing from the spirit and scope of the present invention.

Further, the configurations of the above-described embodiments may beexchanged among them. For example, the shield plate 71 in the thirdembodiment may be applied to the laser irradiation apparatus 1 accordingto the first embodiment.

This application is based upon and claims the benefit of priority fromJapanese patent application No. 2016-197789, filed on Oct. 6, 2016, thedisclosure of which is incorporated herein in its entirety by reference.

REFERENCE SIGNS LIST

-   1, 101 LASER IRRADIATION APPARATUS-   10 LIGHT SOURCE-   20 OPTICAL-SYSTEM MODULE-   21 OPTICAL-SYSTEM HOUSING-   22 MIRROR-   23 SEALING WINDOW-   30 SEALED PART-   31 SEALED HOUSING-   33 SEALING WINDOW-   34 GAS INLET-   35 GAS OUTLET-   37 GAS-   40 PROCESSING CHAMBER-   41 GAS BOX-   42 INTRODUCTION WINDOW-   43 IRRADIATION WINDOW-   44 GAS INLET-   45 SUBSTRATE STAGE-   46 BASE-   47 SCANNING DEVICE-   48 HORIZONTAL BASE-   49 TRANSPORT DIRECTION-   51, 51 a, 51 b SHIELD PLATE-   52, 52 a, 52 b SHIELD PLATE-   54 SLIT-   55 SLIT-   57 REFLECTING MIRROR-   58 HEAT INSULATING MATERIAL-   59 a, 59 b MULTI-LAYER HEAT ABSORBING FILM-   61, 62, 63 REFLECTED-LIGHT RECEIVING COMPONENT-   62 a, 63 a MAIN-BODY PART-   62 b, 63 b HEAT INSULATING AIR LAYER-   62 c, 63 c COOLANT CHANNEL-   63 d HEAT ABSORBING ELEMENT-   71 SHIELD PLATE-   72 HORIZONTAL PART-   73 INCLINED PART-   201 GLASS SUBSTRATE-   202 GATE ELECTRODE-   203 GATE INSULATING FILM-   204 AMORPHOUS SILICON FILM-   205 POLYSILICON FILM-   206 INTER-LAYER INSULATING FILM-   207 a SOURCE ELECTRODE-   207 b DRAIN ELECTRODE-   300 ORGANIC EL DISPLAY DEVICE-   310 SUBSTRATE-   311 TFT LAYER-   311 a TFT-   312 ORGANIC LAYER-   312 a ORGANIC EL LIGHT EMITTING ELEMENT-   312 b SEPARATION WALL-   313 COLOR FILTER LAYER-   313 a COLOR FILTER-   314 SEALING SUBSTRATE-   C1 OPTICAL AXIS-   L1 LASER LIGHT-   M1 SUBSTRATE-   R1 REFLECTED LIGHT-   R2 REFLECTED LIGHT-   R3 REFLECTED LIGHT

1. A laser irradiation apparatus comprising: an optical-system moduleconfigured to apply laser light to an object to be irradiated; a firstshield plate in which a first slit is formed, through which the laserlight passes; and a reflected-light receiving component disposed betweenthe optical-system module and the first shield plate, wherein thereflected-light receiving component is able to receive, out of the laserlight, first reflected light reflected by the first shield plate.
 2. Thelaser irradiation apparatus according to claim 1, further comprising asecond shield plate in which a second slit is formed, through which thelaser light that has passed through the first slit passes, wherein thereflected-light receiving component is able to receive, out of the laserlight, second reflected light reflected by the second shield plate. 3.The laser irradiation apparatus according to claim 1, wherein thereflected-light receiving component receives third reflected light, thethird reflected light being light that is generated as the laser lightthat has been applied to the object to be irradiated is reflected by theobject to be irradiated.
 4. The laser irradiation apparatus according toclaim 3, wherein an incident angle of the first reflected light differsfrom an incident angle of the third reflected light in a part of thereflected-light receiving component where the first and third reflectedlights are received.
 5. The laser irradiation apparatus according toclaim 1, wherein the reflected-light receiving component comprises acooling jacket comprising a coolant channel through which a coolantflows.
 6. The laser irradiation apparatus according to claim 1, whereinthe reflected-light receiving component comprises a heat-insulating airlayer disposed on an optical-system module side, the heat-insulating airlayer containing air.
 7. The laser irradiation apparatus according toclaim 1, wherein the reflected-light receiving component comprises aheat absorbing element disposed on a first shield plate side, the heatabsorbing element being adapted to absorb heat.
 8. The laser irradiationapparatus according to claim 7, wherein a multi-layer heat absorbingfilm is formed over a surface on the first shield plate side of the heatabsorbing element, the multi-layer heat absorbing film comprising aplurality of heat absorbing films adapted to absorb heat.
 9. The laserirradiation apparatus according to claim 8, wherein the multi-layer heatabsorbing film has a predetermined tolerance for an incident angle ofthe first reflected light.
 10. The laser irradiation apparatus accordingto claim 7, wherein a frosting process has been performed over a surfaceon the first shield plate side of the heat absorbing element.
 11. Thelaser irradiation apparatus according to claim 7, wherein a multi-layerheat absorbing film is formed over a surface on an optical-system moduleside of the heat absorbing element, the multi-layer heat absorbing filmcomprising a plurality of heat absorbing films adapted to absorb heat.12. The laser irradiation apparatus according to claim 7, wherein anabsorption ratio of the multi-layer heat absorbing film formed over thesurface on the first shield plate side of the heat absorbing element andcomprising the plurality of heat absorbing films adapted to absorb heatis lower than that of the multi-layer heat absorbing film formed overthe surface of the optical-system module side of the heat absorbingelement.
 13. The laser irradiation apparatus according to claim 1,wherein a reflecting mirror is provided over a surface of anoptical-system module side of the first shield plate.
 14. The laserirradiation apparatus according to claim 13, wherein a reflecting filmapplied to the reflecting mirror has a predetermined tolerance for anincident angle of the laser light.
 15. The laser irradiation apparatusaccording to claim 1, wherein the first shield plate is bent toward theoptical-system module.
 16. The laser irradiation apparatus according toclaim 1, wherein the first shield plate comprises a horizontal part anda part inclined from the horizontal part toward the optical-systemmodule, and the first reflected light includes reflected light, thereflected light being light that is generated as the laser light thathas been applied to the first shield plate is reflected by the inclinedpart.
 17. A method for manufacturing a semiconductor device comprisingthe steps of: (A) emitting laser light from an optical-system moduletoward a substrate on which a film including a semiconductor is formed;(B) providing a first shield plate in which a first slit is formed,through which the laser light passes, and making, out of the laser lightapplied to the first slit and the first shield plate, part of the laserlight applied to the first slit pass through the first slit; (C)blocking, out of the laser light applied to the first slit and the firstshield plate, part of the laser light applied to the first shield plateby the first shield plate; (D) disposing a reflected-light receivingcomponent between the optical-system module and the first shield plate,and making the reflected-light receiving component receive a firstreflected light, the first reflected light being light that is generatedas the laser light is applied to the first shield plate and reflected bythe first shield plate; and (E) irradiating the substrate with, out ofthe laser light applied to the first slit and the first shield plate,the laser light that has passed through the first slit.
 18. The methodfor manufacturing a semiconductor device according to claim 17, furthercomprising the steps of: (F) providing a second shield plate in which asecond slit is formed, through which the laser light that has passed thefirst slit passes, and making, out of the laser light applied to thesecond slit and the second shield plate, part of the laser light appliedto the second slit pass through the second slit; (G) blocking, out ofthe laser light applied to the second slit and the second shield plate,part of the laser light applied to the second shield plate by the secondshield plate; and (H) making the reflected-light receiving componentreceive second reflected light, the second reflected light being lightthat is generated as the laser light that has been applied to the secondshield plate is reflected by the second shield plate.
 19. The method formanufacturing a semiconductor device according to claim 17, furthercomprising a step of making the reflected-light receiving componentreceive third reflected light, the third reflected light being lightthat is generated as the laser light that has been applied to thesubstrate is reflected by the substrate.